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<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
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<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->

<refentry id="systemd-journal-gatewayd.service" conditional='HAVE_MICROHTTPD'
          xmlns:xi="http://www.w3.org/2001/XInclude">

  <refentryinfo>
    <title>systemd-journal-gatewayd.service</title>
    <productname>systemd</productname>
  </refentryinfo>

  <refmeta>
    <refentrytitle>systemd-journal-gatewayd.service</refentrytitle>
    <manvolnum>8</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>systemd-journal-gatewayd.service</refname>
    <refname>systemd-journal-gatewayd.socket</refname>
    <refname>systemd-journal-gatewayd</refname>
    <refpurpose>HTTP server for journal events</refpurpose>
  </refnamediv>

  <refsynopsisdiv>
    <para><filename>systemd-journal-gatewayd.service</filename></para>
    <para><filename>systemd-journal-gatewayd.socket</filename></para>
    <cmdsynopsis>
      <command>/usr/lib/systemd/systemd-journal-gatewayd</command>
      <arg choice="opt" rep="repeat">OPTIONS</arg>
    </cmdsynopsis>
  </refsynopsisdiv>

  <refsect1>
    <title>Description</title>

    <para><command>systemd-journal-gatewayd</command> serves journal
    events over the network. Clients must connect using
    HTTP. The server listens on port 19531 by default.
    If <option>--cert=</option> is specified, the server expects
    HTTPS connections.</para>

    <para>The program is started by
    <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
    and expects to receive a single socket. Use
    <command>systemctl start systemd-journal-gatewayd.socket</command> to start
    the service, and <command>systemctl enable systemd-journal-gatewayd.socket</command>
    to have it started on boot.</para>
  </refsect1>

  <refsect1>
    <title>Options</title>

    <para>The following options are understood:</para>

    <variablelist>
      <varlistentry>
        <term><option>--cert=</option></term>

        <listitem><para>Specify the path to a file or <constant>AF_UNIX</constant> stream socket to read the
        server certificate from. The certificate must be in PEM format. This option switches
        <command>systemd-journal-gatewayd</command> into HTTPS mode and must be used together with
        <option>--key=</option>.</para></listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--key=</option></term>

        <listitem><para>Specify the path to a file or <constant>AF_UNIX</constant> stream socket to read the
        secret server key corresponding to the certificate specified with <option>--cert=</option> from. The
        key must be in PEM format.</para></listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--trust=</option></term>

        <listitem><para>Specify the path to a file or <constant>AF_UNIX</constant> stream socket to read a CA
        certificate from. The certificate must be in PEM format.</para></listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--system</option></term>
        <term><option>--user</option></term>

        <listitem><para>Limit served entries to entries from system
        services and the kernel, or to entries from services of
        current user. This has the same meaning as
        <option>--system</option> and <option>--user</option> options
        for
        <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>. If
        neither is specified, all accessible entries are served.
        </para></listitem>
      </varlistentry>

      <varlistentry>
        <term><option>-m</option></term>
        <term><option>--merge</option></term>

        <listitem><para>Serve entries interleaved from all available
        journals, including other machines. This has the same meaning
        as <option>--merge</option> option for
        <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para></listitem>
      </varlistentry>

      <varlistentry>
        <term><option>-D <replaceable>DIR</replaceable></option></term>
        <term><option>--directory=<replaceable>DIR</replaceable></option></term>

        <listitem><para>Takes a directory path as argument. If
        specified, <command>systemd-journal-gatewayd</command> will serve the
        specified journal directory <replaceable>DIR</replaceable> instead of
        the default runtime and system journal paths.</para></listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--file=<replaceable>GLOB</replaceable></option></term>

        <listitem><para>Takes a file glob as an argument. Serve
        entries from the specified journal files matching
        <replaceable>GLOB</replaceable> instead of the default runtime
        and system journal paths. May be specified multiple times, in
        which case files will be suitably interleaved. This has the same meaning as
        <option>--file=</option> option for
        <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
        </para></listitem>
      </varlistentry>

      <xi:include href="standard-options.xml" xpointer="help" />
      <xi:include href="standard-options.xml" xpointer="version" />
    </variablelist>
  </refsect1>

  <refsect1>
    <title>Supported URLs</title>

    <para>The following URLs are recognized:</para>

    <variablelist>
      <varlistentry>
        <term><uri>/browse</uri></term>

        <listitem><para>Interactive browsing.</para></listitem>
      </varlistentry>

      <varlistentry>
        <term><uri>/entries[?option1&amp;option2=value…]</uri></term>

        <listitem><para>Retrieval of events in various formats.</para>

        <para>The <option>Accept:</option> part of the HTTP header
        determines the format. Supported values are described below.
        </para>

        <para>The <option>Range:</option> part of the HTTP header
        determines the range of events returned. Supported values are
        described below.
        </para>

        <para>GET parameters can be used to modify what events are
        returned. Supported parameters are described below.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><uri>/machine</uri></term>

        <listitem><para>Return a JSON structure describing the machine.</para>

        <para>Example:
        <programlisting>{ "machine_id" : "8cf7ed9d451ea194b77a9f118f3dc446",
  "boot_id" : "3d3c9efaf556496a9b04259ee35df7f7",
  "hostname" : "fedora",
  "os_pretty_name" : "Fedora 19 (Rawhide)",
  "virtualization" : "kvm",
  …}</programlisting>
        </para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><uri>/fields/<replaceable>FIELD_NAME</replaceable></uri></term>

        <listitem><para>Return a list of values of this field present in the logs.</para>
        </listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1>
    <title>Accept header</title>

    <para>
      <option>Accept: <replaceable>format</replaceable></option>
    </para>

    <para>Recognized formats:</para>

    <variablelist>
      <varlistentry>
        <term><constant>text/plain</constant></term>

        <listitem><para>The default. Plaintext syslog-like output,
        one line per journal entry
        (like <command>journalctl --output short</command>).</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><constant>application/json</constant></term>

        <listitem><para>Entries are formatted as JSON data structures,
        one per line
        (like <command>journalctl --output json</command>).
        See <ulink
        url="https://www.freedesktop.org/wiki/Software/systemd/json">Journal
        JSON Format</ulink> for more information.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><constant>text/event-stream</constant></term>

        <listitem><para>Entries are formatted as JSON data structures,
        wrapped in a format suitable for <ulink
        url="https://developer.mozilla.org/en-US/docs/Server-sent_events/Using_server-sent_events">
        Server-Sent Events</ulink>
        (like <command>journalctl --output json-sse</command>).
        </para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><constant>application/vnd.fdo.journal</constant></term>

        <listitem><para>Entries are serialized into a binary (but
        mostly text-based) stream suitable for backups and network
        transfer
        (like <command>journalctl --output export</command>).
        See <ulink
        url="https://www.freedesktop.org/wiki/Software/systemd/export">Journal
        Export Format</ulink> for more information.</para>
        </listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1>
    <title>Range header</title>

    <para>
      <option>Range: entries=<replaceable>cursor</replaceable>[[:<replaceable>num_skip</replaceable>]:<replaceable>num_entries</replaceable>]</option>
    </para>

    <para>where
      <replaceable>cursor</replaceable> is a cursor string,
      <replaceable>num_skip</replaceable> is an integer,
      <replaceable>num_entries</replaceable> is an unsigned integer.
    </para>

    <para>Range defaults to all available events.</para>
  </refsect1>

  <refsect1>
    <title>URL GET parameters</title>

    <para>Following parameters can be used as part of the URL:</para>

    <variablelist>
      <varlistentry>
        <term><uri>follow</uri></term>

        <listitem><para>wait for new events
        (like <command>journalctl --follow</command>, except that
        the number of events returned is not limited).</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><uri>discrete</uri></term>

        <listitem><para>Test that the specified cursor refers to an
        entry in the journal. Returns just this entry.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><uri>boot</uri></term>

        <listitem><para>Limit events to the current boot of the system
        (like <command>journalctl -b</command>).</para></listitem>
      </varlistentry>

      <varlistentry>
        <term><uri><replaceable>KEY</replaceable>=<replaceable>match</replaceable></uri></term>

        <listitem><para>Match journal fields. See
        <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para>
        </listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1>
    <title>Examples</title>
    <para>Retrieve events from this boot from local journal
    in <ulink
    url="https://www.freedesktop.org/wiki/Software/systemd/export">Journal
    Export Format</ulink>:
    <programlisting>curl --silent -H'Accept: application/vnd.fdo.journal' \
       'http://localhost:19531/entries?boot'</programlisting>
    </para>

    <para>Listen for core dumps:
    <programlisting>curl 'http://localhost:19531/entries?follow&amp;MESSAGE_ID=fc2e22bc6ee647b6b90729ab34a250b1'</programlisting></para>
  </refsect1>

  <refsect1>
    <title>See Also</title>
    <para>
      <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>systemd-journal-remote.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>systemd-journal-upload.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
    </para>
  </refsect1>

</refentry>
